UPSTREAM: extcon: Deduplicate code in extcon_set_state_sync()

Finding the cable index and checking for changed status is also done
in extcon_set_state(). So calling extcon_set_state_sync() will do these
checks twice. Remove them and use these checks from extcon_set_state().

Bug: 253534975
Bug: 260915739
Change-Id: Iaff09f32e237751c2a94fdd6a50dbf20d9c9d321
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Link: https://lore.kernel.org/all/20211123145301.778629-1-alexander.stein@ew.tq-group.com/T/
(cherry picked from commit 2da3db7f)